Abrasive fluid pump



April 14, 1959 E. E. WILLIAMS 'ABRASIVE FLUID PUMP 2 Sheets-Sheet 1Filed April '7. 1955 WILLIAMS 0O EARL E I ATTORNEYS Aprifi 14, 1959 E.E. WILLIAMS 2,881,709.

ABRASIVE FLUID PUMP Filed April 7, 1955 2 Sheets-Sheet 2 INVENTOR EARLE. WILLIAMS 1 ATTORNEYS United States Patent O ABRASIVE FLUID PUMP EarlE. Williams, Augusta, Kans. Application April 7, 1955, Serial No.499,918

7 Claims. (Cl. 103-150) The present invention relates to a pumpingsystem, more particularly, to a plurality of hydraulic exchangers forpumping abrasive fluid wherein independent systems are provided forcirculating the abrasive fluid and the clean pumping oil.

Considerable effort has been previously expended in order to deviseeflicient and inexpensive methods for the drilling of oil. One methodwhich has been used with some success involves employing a rotary bitand an abrasive fluid as the drilling agents. In this method an abrasivefluid under high pressure is forced into the proposed oil well. Theaction of this fluid is extremely effective in cutting the dirt andstone ordinarily encountered in drilling oil wells and removing thematerial loosened by the bit.

One common practice of forming an abrasive fluid is by adding claycompounds or the like to a drilling fluid. The drilling fluid primarilyfunctions to cool the rotary bit bearing and to convey rock chips to thesurface. In shallow wells clean water or oil may be employed as adrilling fluid.

The fluid is subsequently pumped from the depths of the well andrecirculated through the abrasive fluid pumps for repeated use. Ifdesired, the recirculated fluid may be passed through purifiers orfilters in order to remove some of the larger pieces of debris which maybe in the fluid.

While this method for oil drilling has considerable merit, a problemexists in devising pumps and pumping systems adequate to handle thetremendous volume of abrasive fluid at high pressures necessary fordrilling extremely deep wells. As the practical limit of piston typepumps is soon reached, attention was directed toward the use ofhydraulic exchangers to pump abrasive fluid. Consequently, hydraulicexchangers in the nature of flexible diaphragm pumps have been employedin oil drilling.

In order to achieve greater volume of abrasive fluid under higherpressure, conventional type pumps were compounded. In general, thecompounding of conventional pumps for pressure proved to be diflicultand not particularly successful.

The use of conventional pumps resulted in the impart ing of certainundesirable characteristics to the pumped abrasive fluid. Pulsations dueto the opening and closing of valves were transmitted to the abrasivefluid. These pulsations were undesirable as they combined to decreasethe eificiency of the drilling process.

It has been found that a pumping system comprising a plurality ofhydraulic exchangers could be successfully employed in the pumping ofabrasive fluid. With this object in mind, a valving system was devisedwhich as sured that only the pump pulsations appeared in the abrasivefluid flow. By employing a rotary type multiunit valve, pulsations dueto the opening and closing of the various valves were eliminated.

Additional improvements to abrasive fluid pumping 2,831,709 PatentedApr. 14, 1959 'ice systems have been made in the structure by thehydraulic exchanger itself. The diaphragm of the hydraulic exchanger hasbeen made of two flexible elements with a suitable detectable fluidcontained therebetween. Detector means are installed in each of theoutlets of the hydraulic exchanger. Consequently, rupture of thediaphragm would result in a portion of the detectable fluid escapingthrough one of the outlets. The presence of the detectable fluidaccordingly actuates the detector means. Rather than cease operation ofthe system, means have been provided to enable a stand-by hydraulicexchanger to be substituted for the damaged hydraulic exchanger. Thisfeature results in a continuous and uninterrupted abrasive fluid flowfrom the hydraulic exchanger system.

It is, therefore, the principal object of this invention to provide animproved hydraulic exchanger system adapted to the pumping of abrasivefluid.

It is another object of this invention to provide a valving system for ahydraulic exchanger system whereby only the pump pulsations aretransmitted to the abrasive fluid.

It is a further object of this invention to provide a hydraulicexchanger system which will permit continuous uninterrupted service.

It is an additional object of this invention to provide improvements inflexible diaphragm pumps.

It is still another object of this invention to provide a rotary valvefor transmitting pump characteristics to a pumped abrasive fluid.

It is a still further object of this invention to provide a hydraulicexchanger system which will impart certain desirable characteristics topumped abrasive fluid under conditions of high volume and high pressure.

Other objects and advantages of this invention will become readilyapparent upon reference to the accompanying description when taken inconjunction with the following drawings, wherein:

Figure 1 is a schematic view of the hydraulic exchanger system disclosedas this invention;

Figure 2 is a diametrical sectional view of a hydraulic exchangeremployed in the system illustrated in Figure 1;

Figure 3 is an overall perspective view of the rotary multi-unit valveemployed in the hydraulic exchanger system of this invention;

Figure 4 is a sectional View taken along the lines 44 of Figure 3;

Figure 5 is a sectional view taken along the lines 5-5 of Figure 3 andshowing the suction and discharge grooves on the suction valve bodyportion;

Figure 6 is a plan view of the slotted rotary valve member employed inthe rotary valve illustrated in Figures 3 and 5;

Figure 7 is a sectional view taken along thelines 77 of Figure 4;

Figure 8 is a schematic view showing the shifting system forsubstituting a stand-by hydraulic exchanger in the event of failure of aregular hydraulic exchanger;

Figure 9 is a longitudinal sectional view of the preloaded spring andhousing connection employed in the system shown in Figure 8; and IFigure 10 is a schematic view of a modification of the shifting systemfor operatively connecting a stand-by hydraulic exchanger. t 1 iProceeding now to the drawings, more particularly to Figure 1, it ispointed out that like reference symbols indicate the same partsthroughout the various views. The clean oil pumping system illustratedin Figure 1 comprises a clean oil vacuum tank 10 having a vacuum pump11A, and heating coils 11 and cooling coils 12 therein to maintain theoil at a constant temperature. Conduits 13 3 and 14 lead to and from theheating coils 11. A suitable coolant is conveyed into the cooling coil12 by means of the inlet conduit 15 and the outlet conduit 16.

Located Within the tank 10 is a high-volume low pressure booster pump17'. The booster pump 17 discharges oilinto a conduit 18: which is thesuction line of a pump 19.. The pump 19. is of the radial type and hascontrol means for shifting to neutral or to an inoperative position.

The pump 19 discharges the clean oil through a conduit 20to a rotarymulti-unit valve indicated at 21. The valve 21 essentially comprises adischarge valve body portion'22' and a suction valve body portion 23.The specific structure of the rotary valve 21 is illustrated in Fig ures3 through 7 and will be later describedin detail; The valve 21 regulatesthe flow of clean oil through the discharge'conduits 24A through D to aplurality of hydraulic exchangers 25A through D respectively. The valve21 also controls the flow of fluid to and from a stand-by hydraulicexchanger indicated at 258 through a discharge conduit 24S and a suctionconduit 265. The function of the stand-by hydraulic exchanger 258 willalso be described later.

The clean oil is withdrawn from each of the hydraulic exchangers throughsuction conduits 26A through D which connect the respective hydraulicexchangers to the suction valve body suction portion 23. The clean oilis then passed through the conduit 27 and is returned to the vacuum tank10 for recirculation.

Valves 28 and 29 are installed in the discharge and suction conduits 20and 27 respectively, in order to bypass the hydraulic exchanger systemto enable the oil to be used atan'alternate location.

Each of the hydraulic exchangers 25 is connected between a suction line30 and a discharge line 31. These connections are achieved by providinga plurality oflead suction conduits 32 between the exchangers 25 andthesuctionconduit 30. A valve 33 is inserted in each of the connectingconduits 32. Similarly a discharge connecting conduit 34 is used toconnect each of the hydraulic exchangers 25 with the discharge line 31.Again, similarly,

a valve 35 is provided in each of the discharge connecting conduits 34.

Proceeding now to Figure 2, there is illustrated a diametrical sectionalview of one ofthe hydraulic exchangers 25. Hydraulic exchanger 25 isessentially spherical in shape and comprises a clean oil half 36 and anabrasivefluid half 37. Each of the halves 36 and 37 has an externalflange 38 and 39, respectively, thereon. The flanges 38 and 39 areadapted to cooperate with each other and the halves 36 and 37 aresecured together through suitable means interconnecting the two externalflanges.

A flexible diaphragm 40 has a periphery projecting between-the flanges38 and 39 and is secured in position by being clamped therebetween. Thediaphragm 40' comprises flexible elements 41 and 42. A suitabledetectable fluid indicated at 43 is contained between flexible elements-41 and 42. The fluid 43 may be rendered detectable by use of radioactiveparticles therein. The amount ofradioactivity is small and is onlynecessary to actuate detector instruments. Suitable detector means, suchas a Geiger counter or the like, indicated at 44, are positioned in thedischarge outlet 34 and the clean oil suction oil conduit 26 for each ofthe hydraulic exchangers 25.

A perforated steel plate 45 is positioned in the clean oil chamber toprevent over-extension of the diaphragm 40 or suction of the diaphragminto the clean oil suction line 26. Protection of the diaphragm 40 isachievedin the abrasive fluid discharge half of the hydraulic exchangerby connecting an emergency relief valve 46 thereto.

An additional safety feature is incorporated in. the. hydraulicexchanger 25. This feature comprises a springloaded semi-flexible meshdiaphragm 47 positioned. adjacent the flexible diaphragm 40 on theabrasiveside of the exchanger. This diaphragm assures the completion ofthe suction portion of the cycle when very viscous and heavy abrasivefluids are being handled.

Proceeding now to Figure 3, there is illustrated the rotary multi-unitvalve 21. As described previously, the valve comprises a discharge valvebody half 22 and a suction valve body half 23 which have opposedcooperating faces 48 and 49 respectively. The valve body halves may besecured together by suitably bolting external flanges 50 and 51 whichare respectively connected to the respective valve body halves 22 and23.

Located in the discharge valve body half 22 is an anrrular dischargechamber 52. A passage 53 interconnects the discharge chamber 52 with thedischarge conduit 20.

Inner faces 48 and 49 of the valve body portions have a plurality ofarcuate grooves therein. The pattern of grooves on each face isreversed. Consequently, when the valve body halves are assembled thegrooves will cooperate. Figure 5 indicates the pattern of the grooves inthe suction valve body portion 23. These grooves comprise, dischargegrooves 54 and suction grooves 55. There is a set of grooves comprisinga discharge and suction groove for each of the units 25A through Dserviced by the rotary valve. The opposed sets of grooves are located atvarying distances from the center of the rotary valve.

Each of the discharge grooves 54 is connected to the discharge chamber52 by means of the passages 56A through D. In addition, there arepassages 57 which connect each of the suction grooves 55' in thedischarge portion 22 with the suction conduits 26A through D.

The suction valve body 23 similarly has an annular space defining asuction chamber 58 therein. This chamber is connected by means of apassage 59 to the suction conduit 27. There are a plurality of axiallyextending passages 60 which connect the suction chamber 58 with each oneof the suction grooves 55 located in the inner face of the suction valvebody portion. Also formed. Within the suction valve body 23 are passages61 which interconnect the discharge grooves 54 in the suction valve bodyportion with the discharge conduits 24A through D.

The valve structure enables the discharge oil to enter the chamber 52 ofthe discharge valve body portion 22 where it passes through the passages56, discharge grooves 54, slotted openings in a valve plate to bepresently described, through the passages 61 and discharged through theconduits 24, which project from the suction valve body portion 23, tothe respective hydraulic exchangers.

The suction valve body portion 23 has an axial bore 62 therein whichreceives a shaft 63 upon the inner end of which is secured a disc-likerotary valve plate 64. The shaft 63 is driven by a suitable electricmotor, as indicated at 65 in Figure l.

The valve plate 64 is illustrated in Figure 6 and comprises a pluralityof arcuate slots 66 through 69. Each of the slots 66 through 69 islocated a diflerent distance from the center of the valve plate. As thedischarge and suction grooves 54 and 55A through D are also located atfour equal distances from the center of the valve body, it can be seenthat the slots in the valve plate readily cooperate with the grooves inthe valve body. Consequently, continuous rotation of the valve plate 64will continuously expose varying areas of the grooves 54 and 55. As thegrooves 54 and 55 function as ports, it can be seen that the open portarea will be regulated by the rotation of the rotary valve plate.

The spacing and length of both the grooves and the valve plate slots isof extreme importance. One of the objects of this invention is toachieve a hydraulic exchanger system wherein only' the pump pulsationsare transmitted to the hydraulic exchanger. It has been found that bymaintaining, a constant open area of the discharge orthe suction partsat any point of rotation of the valve. plate, a faithful transmission ofpump characteristics:

will be achieved.

To clarify the various relationships between the various exposed portareas, reference is made to Table I.

TABLE I Part area table of clean oil Suction At Movement 45 ClockwiseDischarge 1st Allof 4+%of 1+% of 3 All of 2. 2nd +A110f4 of 2+% of 1.

A of 2+A11 of 3+% of 4 All of 1.

+All of 3 i. of 1+% of 4. of 3| %fi ff1-1i-All of 2 g f 4y 4 a o 3 0 11of1+% of 2+% of 4 A 1] of a. 2 All of 4+All of 1 l of 2+% of 3. BeginNew Cycle Begin new cycle.

The figures 1, 2, 3 and 4 represent the port areas associated with thehydraulic exchangers A, B, C, and D respectively.

Table I shows the open port areas for both the discharge and suctionports at positions of the rotary valve plates spaced 45 apart. Regardingthe valve body and the rotary valve plate in the initial or 0 positions,as depicted in Figures 5 and 6 respectively, reference to Table I willreveal that of the suction grooves all of D and one-half of A andone-half of C will be open. Of the discharge grooves all of groove Bwill be open. Rotation of the valve plate in increments of 45 in aclockwise direction will result in the open port areas as listed inTable 1.

Examination of Table I will reveal that at all times total areacomprising a complete discharge port will be open. However, if desired,any other relationship of open suction and discharge ports may bereadily attained by varying the positioning and lengths of the slots inthe rotary valve plate.

Although the grooves in the valve body portions are of varying linearlength, each of the grooves subtends the same angle. This angle issomewhat less than 90.

Therefore, use of the above defined relationships of the grooves andslots will result in the pump pulsations from the radial pump beingfaithfully duplicated in the abrasive fluid flow pumped by the hydraulicexchangers.

Proceeding now to Figure 8, there is illustrated therein a system forshifting a stand-by hydraulic exchanger into regular operation in orderto achieve continuous uninterrupted service from the pumping system.

In this system a separate hydraulic valve 70 (AD) controls the flow ofhydraulic fluid to each of the hydraulic exchangers. The hydraulic valve70A is of the balanced type and is actuated by means of a rod 71 whichis axially movable in order to expose either the discharge or suctionports of the hydraulic valve. The actuating rod 71 is connected to apre-loaded spring and housing assembly indicated at 72 and illustratedin Figure 9. Extending from the other end of the pre-load and springassembly is a cam shaft 73 which passes through a bearing 74 located ina valve stem guide plate 75. The lower end of the cam shaft 73 isengageable With a cam surface 76 located adjacent the periphery of arotary cam plate 77. The cam plate 77 is secured to a drive shaft 78which also passes through a suitable bearing located in the center ofthe valve stem guide plate 75. The drive shaft 78 is connected by meansof suitable gearing indicated at 79 to a power source.

Each of the operating rods 71 has a stop collar or notch 80 thereon. Thenotch is adapted to be engaged by a trigger 81 operated by a solenoid82. In normal position the trigger 81 is withdrawn into the solenoid 82to cause the trigger 81 to be disengaged from the notch 80.

i It should be borne in mind that the valve stem guide plate 75 inFigure 8 is circular with the bearings 74 being equally spaced adjacentthe periphery thereof.

Figure 8 is schematic to clarify the operation of the shifting system.

A balanced hydraulic valve 83 for the stand-by hydraulic exchanger ispositioned on the other side of the cam 77. The hydraulic valve 83 issimilarly operated by an operating rod 84 which engages the centralportion of a plunger plate 85. Equally disposed about the periphery ofthe plunger plate 85 and aligned with the hydraulic valves 70 A-D is alike plurality of plungers 86, each of which is engageable with theplunger plate 85. Each of the plungers 86 has a pre-loaded springassembly 87 connected thereto and has a cam shaft 88 extending from theother side of the assembly to be engageable with a cam surface89'located on the cam 77 and aligned with the cam surface 76. Thepre-loaded spring assembly 87 is similar to the spring assembly 72depicted in Figure 9.

Each of the plungers 86 has a stop collar or notch 90 thereon which isengageable with a trigger 91 actuated by a solenoid 92. The normalposition of the trigger 91 is in engagement with each of the notches 90upon the plungers. Consequently, when the cam surface 89 depresses thecam shaft 88, as indicated at A in Figure 7, trigger 91 will restrainaxial movement of the plunger 86 and, consequently, there will be nomovement of the plunger plate 85.

The cam shafts 88 also pass through bearings 93 which are placedadjacent the periphery of a valve stem guide plate 94 which is similarto the valve stem guide plate 75. There is a thrust bearing 95 in thecentral portion of the valve stem guide plate 94 to accommodate the endof the cam drive shaft 78.

With the arrangement as illustrated in Figure 8, it can be seen thatrotation of the cam plate 77 will result in sequential operation of eachone of the hydraulic exchanger valves 70 A-D. Upon failure of any one ofthe hydraulic exchangers as will be indicated by the leakage ofdetectable fluid through one of the outlets, the respective detectormeans 44 will be energized to actuate the respective solenoid 82. Thisenergization of the solenoid 82 will result in the trigger 81 beingengaged with the stop collar 80. Consequently, that hydraulic valvewould be rendered inoperable.

Simultaneously with the energization of the solenoid 82, thecorresponding solenoid 92 will be energized to draw the trigger 91 fromengagement in the notch 90. This would result in the plunger 86 beingoperatively engageable with the cam surface 89 on the cam plate 77.Depression of the plunger 86 would depress the plunger plate 85. Thisdepression or tilting of the plunger plate 85 would depress the stand-byhydraulic exchanger valve 83. Consequently, the stand-by hydraulicexchanger valve 83 would be substituted for the operation of thehydraulic exchanger which had failed. This would result in continuousuninterrupted service of the hydraulic exchanger system.

During the operation of the stand-by hydraulic exchanger, the damagedhydraulic exchanger 25 may be repaired. Upon completion of the repairsboth solenoids 92 and 82 would be de-energized and stand-by hydraulicexchanger valve 83 would not be operated by the plunger plate 85. Therepaired hydraulic exchanger would then resume operation in normalsequence with the remaining hydraulic exchangers.

In Figure 10 there is illustrated an alternate shifting system which isadapted for use with the rotary valve 21 previously described. Figure 10illustrates diagrammatically the suction valve body portion 23 with thedischarge conduits 24A through D extending therefrom. Connected in eachone of the discharge conduits 24 is a solenoid operated two-way valve96. There is a conduit 97 extending from each of the valves 96 to thestand-by hydraulic exchanger 25.

Upon failure of the hydraulic exchanger 25A, the solenoid operated valve96A will be energized to divert 7 theflow of fluid through the conduit97 to the stand-by hydraulic exchanger 25. This operation of the.solenoid operated valve 96A will occur in sequence to substitute thestand-by hydraulicexchanger 258 for theinoperative-hydraulic exchangerA.

A similar arrangement is connected to the suction conduits 26A throughD. Consequently, the discharge and withdrawal of clean oil to thestand-by exchanger- 258 will. occur in sequence during that period oftime that the hydraulic exchanger 25A is inoperative.

Consequently, either of the arrangements illustrated in Figures 8 and 10will enable a hydraulic exchanger pumping. system to render continuousand uninterruptedservice in the event of failure of one of the hydraulicexchangers.

Thus it can be seen that a hydraulic exchanger system abrasive fluidunder extremely high volume and pres sure conditions. By alternatelyinjecting and withdrawing clean oil in a pre-determined sequence intoeach one of the hydraulic exchangers, it can be seen that the abrasivefluid is discharged from the lines of the hydraulic exchanger under anextremely high pressure. Furthermore, with the relationship of theexposed ports as disclosed in this invention, no pulsations due to theoperation of the valve will be transmitted to the abrasive fluid. Onlypump pulsations will be imparted to the abrasive fluid discharged in thehydraulic exchanger system. This will result in a smooth and aneffective flow of abrasive fluid to accomplish the task of drilling.

Other than some hydraulic losses, there is virtually a perfect exchangeto pumped abrasive fluid through the flexible membranes of each of thehydraulic exchangers.

In addition, this pumping system may be readily used for otherspecialized operations in drilling. One such operation would be inpumping a concrete mixture into a Well. Outside of the field ofdrilling, acids and many other fluids may be pumped within either interor intra plant pipe-lines using the hydraulic exchanger system of thisinvention.

It will be understood that this invention is susceptible to modificationin order to adapt it to diiferent usages and conditions, and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

What is claimed is:

1. In a pumping system, a plurality of hydraulic exchangers for normaloperation and connected in parallel to a suction line and a dischargeline, a stand-by hydraulic exchanger, a hydraulic valve to controlactuated fluid flow into each of said hydraulic exchangers, saidhydraulic exchanger valves being annularly arranged, pre-loaded springmeans on each hydraulic valve for actuating each of said hydraulicexchanger valves, a rotary cam with one face thereof having a camsurface to sequentially engage said actuating means, the hydraulic valvefor said stand-by hydraulic exchanger being positioned facing theopposite face of said rotary cam, a plurality of second spring-loadedactuating means aligned with said first actuating means and each beingconnected to operate said stand-by hydraulic exchanger valve, a secondcam surface on the opposite face of said rotary cam and aligned withsaid first cam surface, means normally engaging said second actuatingmeans for maintaining said second actuating means inoperative, meansengageable with said pre-loaded spring means for selectively renderingone of said hydraulic exchanger valves inoperative,- and meansengageable with said means for maintaining said second actuating meansinoperative for rendering the corresponding second actuating meansoperative simultaneously with the rendering of a hydraulic exchangevalve inoperative whereby said standby hydraulic exchanger issubstituted for said one hy.-. draulic exchanger.

2; In a hydraulic exchanger pumping system, a hydraulic exchanger havinga housing, a flexible diaphragm within saidthousing dividing theinterior thereof into two chambers, the first of said chambers beingprovided'for a work fluid to be pumped and the second for clean oil. asan actuating fluid to actuate said flexible diaphragm to eft'ectpumpingof said work fluid from said first chamber,

I a resiliently mounted semi-flexible mesh diaphragm posi tionedadjacent said flexible diaphragm in said first chamber for assuring thecompletion of the suction portion of the exchanger cycle when variousviscous and heavy abrasivetfiuids are being handled, means in saidhousing providing an inlet and outlet for each of said chambers, means.connected to said first chamber for introducing a work fluid into saidfirst chamber, means connected to. saidisecondl chamber for deliveringclean oil under pres. sure, tov said second chamber to urge saidflexible diaphragm. into said first chamber and thereby forciblydischarge the work fluid from said first chamber, and means. connectedto said means for delivering clean oilandv operable independently ofsaid housing and flexible diaphragmfon cycling the admission anddischarge of; said clean oihintosaid second chamber.

3. In a hydraulic exchanger pumping system, a hy.-'

draulic exchanger having a housing, a flexible diaphragm within saidhousing dividing the interior thereof into two chambers, the saiddiaphragm comprising a pairof spaced flexible elements and a detectablefluid contained. between said elements whose presence in either the workfluid or clean oil will indicate a break in the diaphragm, the first. ofsaid chambers being provided for a work fluid to be pumped and thesecond for a clean oil to actuate said flexible diapragm to effectpumping of said work fluid from said first chamber, means in saidhousing providing an inlet and outlet for each of said compartments,means connected to said first chamber for introducing work fluid intosaid first chamber, means. connected to said second chamber fordelivering clean oil under pressure to said second chamber to forcesaid. flexible diaphragm into said first chamber and thereby forciblydischarge the work fluid from said first char-n ber, and means connectedto said means for delivering clean oil and operable independently ofsaid housing and diaphragm for cycling the admission and dischargeof;said clean oil into said second chamber.

4. In a hydraulic pumping system as claimed in claim 3 with saiddetectable fluid comprising radioactive parti cles' therein whereby uponfailure of the diaphragm the radioactive particles will becomeintermixed either with the clean oil or the work fluid or both and canbe readily detected to reveal the presence of a break in the diaphragm.

5. In a hydraulic pumping system as claimed in claim 4 comprisingmeans-at both outlets of both chambers for detecting the presence ofradioactive particles in the clean oil and the work fluid whereby a leakin the diaphragm will be indicated.

6. In a hydraulic exchanger pumping system, a plurality of hydraulicexchangers operable in succession in a. predetermined sequence, eachexchanger including a housing, a flexible diaphragm in said housingdividing the interior thereof into two chambers, the first of saidchambers being provided for a work fluid to be pumped and the second forclean oil for actuating the flexible dia-vv phragm to effect pumping ofsaid Work fluid from its associated first chamber, means in said housingproviding an inlet and outlet for each of said chambers, means,connected to said first chamber for successively int roducing work fluidinto the first chamber of the respective hydraulic exchangers, meansconnected to said second chamber for successively delivering clean oilunder pressure to the second chamber of the respective exchangers toforce the flexible diaphragm associated therewith into the first chamberand thereby forcibly discharge the work fluid from said first chamber,separate conduit means for said clean oil and said work fluid, andcontrol means connected to said means for delivering clean oil andoperable independently of said exchanger housing and the flexiblediaphragm for so controlling the clean oil that it is successivelyintroduced and exhausted from the second chambers of saidhydraulicexchangers to provide a continuous pumping movement of theflexible diaphragms.

7. In a hydraulic exchanger pumping system, a plurality of hydraulicexchangers operable in succession in a predetermined sequence, eachhydraulic exchanger including a housing, a flexible diaphragm in saidhousing dividing the interior thereof into two chambers, the first ofsaid chambers being provided for a work fluid to be pumped and thesecond for a fluid under pressure for actuating said flexible diaphragmto effect pumping of said work fluid from its associated first chamber,means in said housing providing an inlet and outlet for each of saidchambers, means connected to said first chamber for successivelyintroducing work fluid into the first chamber of the respectivehydraulic exchangers, means connected to said second chamber forsuccessively delivering actuating fluid under pressure to the secondchamher of the respective hydraulic exchangers to force the flexiblediaphragms associated therewith into the first chamber and therebyforcibly discharge the work fluid from said first chamber, separateconduit means for said fluid under pressure and said work fluid, andcontrol means connected to said means delivering fluid under pressurefor cycling the admission and discharge of said fluid under pressuresuccessively to said hydraulic exchangers comprising a rotary valvehaving a constant open area of the chamber inlet means and outlet meansat any point of the rotation of the valve whereby the pulsations of thepump delivering the fluid under pressure will 'be faithfully duplicatedin the work fluid flow pumped by the hydraulic exchangers.

References Cited in the file of this patent UNITED STATES PATENTS1,256,127 Gould Feb. 12, 1918 1,627,257 Stevens May 3, 1927 2,566,873Britton Sept. 4, 1951 2,578,160 Van Der Werfl Dec. 11, 1951 2,593,733Davies Apr. 22, 1952 2,662,478 Surre Dec. 15, 1953 2,673,525 Lucas Mar.30, 1954 2,691,943 Wilson Oct. 19, 1954 FOREIGN PATENTS 147,826 SwedenNov. 23, 1954 888,626 Germany Nov. 26, 1953

